PMID: 22266822 , Related PDB ids: 3AYF, 3AYG

Authors:

Matsumoto Y, Tosha T, Pisliakov AV, Hino T, Sugimoto H, Nagano S, Sugita Y, Shiro Y

Title:

Crystal structure of quinol-dependent nitric oxide reductase from Geobacillus stearothermophilus.

Journal:

Nat Struct Mol Biol. 2012 Jan 22;19(2):238-45. doi: 10.1038/nsmb.2213.

Abstract:

The structure of quinol-dependent nitric oxide reductase (qNOR) from G. stearothermophilus, which catalyzes the reduction of NO to produce the major ozone-depleting gas N(2)O, has been characterized at 2.5 A resolution. The overall fold of qNOR is similar to that of cytochrome c-dependent NOR (cNOR), and some structural features that are characteristic of cNOR, such as the calcium binding site and hydrophilic cytochrome c domain, are observed in qNOR, even though it harbors no heme c. In contrast to cNOR, structure-based mutagenesis and molecular dynamics simulation studies of qNOR suggest that a water channel from the cytoplasm can serve as a proton transfer pathway for the catalytic reaction. Further structural comparison of qNOR with cNOR and aerobic and microaerobic respiratory oxidases elucidates their evolutionary relationship and possible functional conversions.